Telescoped open web beam construction



Dec. 13, 1955 R J, SHORT ETAL 2,726,743

TELESCOPED OPEN WEB BEAM CONSTRUCTION 3 Sheets-Sheet 2 Filed May 21, 1951 ROBERT J. SHORT 8 ROY A. BADT! INVENTORJ'.

HUEBNER BEEHL ER,

WORREL 8 HERZ/Gv ATTORNEYS.

Dec. 13, 19 5 SHORT HAL 2,726,743

TELESCOPED OPEN WEB BEAM CONSTRUCTION Filed May 21, 1951 3 Sheets-Sheet 3 M=275, 000 F [L85- ]=/46.000 FILES. I=28Z000 F7185.

Roe 5R7 .1. SHORT &

ROY A. BADT,

INVENTORS.

HUEBNER, BEE/MEI? WORRE'L 8 HERZ/G! ATTORNEYS.

United States Patent TELESCOPED OPEN WEB BEAM CONSTRUCTION Robert J. Short, North Hollywood, and Roy A. Ba-fit, Beverly Hills, Calif.

Application May 21, 1951, Serial No. 227,394 1 Claim. (Cl. 189-37) This invention relates to a telescoping bridge girder of preferred open web construction suitable especially for a military bridge. Thus the invention relates to a structure useful in solving the problem of extending a bridge girder or plurality thereof over a river, a chasm, or. other inaccessible place, from a bridgehead, usually upon only one side thereof.

In meeting the requirements of a military bridge in particular, it is necessary to achieve convenience and ease of transport of bridge girders useful in being extended longitudinally from one abutment to another, as from a bridgehead to pontoons, or the like. Suitable girders, therefore, must be initially short enough to be hauled upon an average truck, but must be expansible to a sufficient length to be useful as a significant structural element. The parts should be of a minimum number and the total girder should be light enough in weight to be handled and extended or retracted by manpower alone, or with the aid of a minimum number of simple readily available tools, since assembly and launching, normally necessary under extremely diflicult or emergency conditions, and frequently in the face of enemy fire, should require a minimum of special or complicated equipment.

The girder, as an individual element, should be capable of combination in parallel with other similar girders for varying conditions of load and width of road bed. Un-

forseen'field conditions make it impossible to determinein advance any required span. The span, therefore, of a preferred girder for this type'of use should be variable to suit any likely field condition.

The United States production. facilities for'steel girders, as well as the specifications therefor, are well established, and to alter their specifications and the machinery for creating them, would normally serve to hinder a nationwide productive effort designed to meet pressing military requirements, so that it is further desirable that the girders in question be producible fromstandard shapes, as now conventionally formed in steel plants throughout the nation.

It is among the objects of this invention to provide a versatile type of substantially packaged open web girder capable of fulfilling the above stated requirements;

It is also among the objects of this invention to provide a bridge girder of the desired character described, having a minimum over-all length in the telescoped condition thereof and a maximum overall length in the fully extended condition thereof, which has a minimum of weight for convenience of transport and handling, and which is of a shape and construction affording and incorporating features of strength and correct engineering for meeting load requirements.

Another object of the invention is to provide a new and improved bridge girder of expansible form, all parts of which are readily accessible for relative extended or retracted securement.

Another object of the invention is the provision in a new and improved bridge girder of the desired character described, of new. and improved extensible'and retaining means.

Another object of the invention is the provision of new and improved means' for facilitating expansion and retraction of .the girders in question.

Yet another and further object of the invention is the provision of new and improved lateral bracingmeans in expansible girder construction.

The invention also includes among its objects the provision of improvements over prior art devices heretofore intended to accomplish generally similar purposes- Other objects and purposes will appear and be more fully set forth in the accompanying description considered in' the light of. the appended claim and accompanying drawings.

in the drawings:

Figure l is a schematic side elevational view of a preferred form of expansible girder embodying this invention.

Figure 2 is a schematic plan view of a bridge composed of similar girders.

Figure 3 is a fragmentary view, partially cut away, of such a girder in fully telescoped condition.

Figure4 is a view seimilar to Figure 3 but showing the sections of the girder in a condition of selected extension.

Figure 5 is a fragmentary exploded viewof such girder in perspective.

Figure 6 is a vertical sectional view on a line 66 of Figure 3.

Figure 7 is a moment diagram showing the load carrying. capacity and characteristics? of a second preferred form of girder schematically illustrated therewith and embodying this invention.

Referring more particularly to the drawings, and specifically Figures 1 through 6' thereof, one preferred form of girder, there designated generally by the numeral 29, comprises a mid-section 21,.intermediate sections 22 and 23,. and end sections 24 and 25, in' any desired numher.

The central section 21 is'preferably approximately twice the length ofeither the intermediate sections 22 and 23 or the end sections 24 and 25, the intermediate and end sections being approximately equal in length. In the telescoped position of the sections, the intermediate and end ones respectively abut one another at the center of the central section. Said central section is of greater depth and thickness than the intermediate sections, and the intermediate sections have a greater depth and thickness than the end sections, in order that the parts may telescope. Similarly, the'webs 26 and 27 of the central section are separated as by' spacing plates 28 welded at 29 to the confronting edges of the flanges 30 and 31 of the open web I- beams 32 and 33' forming said center section.

In order to permit the intermediate sections to be telescoped or extended readily from within the center section, the I beams 34 and 35 comprising the same are secured in spaced relation as by welded plates 36 on the outer surfaces of the flanges 37 thereof.

The plates36, in addition to. serving as spacers, may be employed as jackingbars to assist in the extension or retraction of the section by the employment of a: simple lever lodging as between the spacers 36 and plates 28.

The end-sections-24 and 25 aretpreferably welded at 38 between adjacent flanges 39 thereof.

In order to further facilitate" the telescoping and retracting action, axles 40 are welded or otherwise secured in place transversely of the webs 41 of the beams comprising the center sections. For such purpose the webs are reinforced as by sleeves 42, preferably extending through and welded to the webs, but optionally comprising short sleeves welded to the inner and outer sides of said webs.

Rollers 43, optionally of a ball bearing type, are secured on the axles as by peening 44, and other rollers 45 of smaller diameter are spaced along the axles 40 as by retaining washers 46.

As' may' be seen most clearly inFigure 6, the rollers 43 are adapted to engage against the inside, whether at the top or at the bottom, of the center section, the inner portions of the flanges thereby facilitating relative longitudinal movement of the intermediate sections within the central section. The rollers 45 similarly engage against the outer sides, whether at the top or at the bottom of the end sections, also retaining longitudinal rigidity between the intermediate and end sections and facilitating longitudinal movement between said sections.

To retain the sections in any desired position of such longitudinal extension, a pin 47 is insertable through the several webs and reinforcing sleeves 48 welded thereto or therethrough. The pins 47 are secured by nuts 49 threaded to one or both ends of said pins, inasmuch as said flanges 4S and their corresponding openings 50 in the webs of the several sections and degrees of extensibility of the sections can thereby be established or varied to suit conditions.

As can be seen most clearly in Figures 2 and 5, any lateral spacing 51 comprising, most desirably, open web structural sectionsmay be secured to the webs of the several girder sections at spaced positions therealong, by bolting as to end pieces 55 welded to the ends of the girders. End pieces like 55' are also used to make up the girder 21 as by the use of bolts 56. Girder 21 is made up of two sets of I sections 32, 33, or additional sections interposed to lengthen the section.

In use, one end, as 52, of the girder 20 can be anchored on a bridgehead, abutment, pontoon or other fixed station, while the sections are successively extended out over an area to be spanned. Men can walk out over the girder as needed for extension thereof and simultaneous securement of the sections to one another.

It is particularly to be noted that an open web type of section as herein illustrated can be made to suit any desired dimensions from standard rolled channels, as noted hereinafter, or from I beams as heretofore described. Thus an open web beam made from a 12" standard rolled section can be fabricated into any depth from 14" to 22" inclusive, thus alfording not only a freedom of design which results in a substantially stronger member than the original rolled. section, but which likewise permits the various lengths to slide within each other so that the over-' all shipping length is no longer than the designed middle section. 'This flexibility of open web fabrication insures not only that the maximum depth of each section will be obtained in order to assure maximum strength, but the open portions 53 provide access openings for the purpose of bolting sections together, as well as for inserting various forms of levers and pry bars to facilitate handling and telescoping the girders.

This invention features the provision of girders formed preferably of open web beams in order to preserve maximum strength associated with minimum weight and utmost accessibility. It likewise features a new and improved girder construction serviceable as a bridge foundation, capable of being anchored at one end in the short or telescoped condition thereof and further capable of extension section by section, without disassembly of the several sections, for spanning an otherwise inaccessible, area. The instant structure may also be employed between pontoons to bridge a river or other body of water.

If one end of the girder is held down and secured and a point spaced outwardly therefrom is supported upon a fulcrum, a workman may climb out upon outhanging structure and by successfully extending and securing the telescoped sections from and to one another, reach a vantage point by means of and for directly anchoring the other end of the girder.

The instant construction issuch, as may be observed by reference to Figure 7, that the greatest strength of the sections occurs towards the center, so that optimum loads both moving and stationary, are supportable upon any girder. This consideration is in addition to the fact of extensibility.

While we have herein shown and described our invention is what we have presently conceived to be the most practical and preferred embodiments, it is recognized that departures may be made therefrom within the scope of our invention, which is not to be limited .to the details disclosed herein, but is to be accorded the full scope of the claim so as to embrace any and all equivalent structures.

We claim: I a A girder comprising: a pair of open-web I-beams, means, at longitudinally spaced stations connecting adjacent flange edges of the beam in a manner to secure; said beams in spaced parallelrelationship defining a con-' tinuous passageway therebetween, bounded on its sides by the respective webs of the beams and on its top and bottom by the respective adjacent upper and lower flanges ofsaid beams and said connecting means, said adjacent flanges at the bottom of the passageway defining a pair of spaced tracks therealong, said adjacent parallel flnges at the top of the passageway defining a. pair of tracks therealong opposed to said lower tracks, a second pair of open-web I-beams of lesser height and width than said passageway in said first pair of I-beams, means securing said second pair of I-beams in parallel relationship at the adjacent corresponding edges of their upper and lower flanges, said second pair of I-beams being retractible and extensible in the passageway defined by said first pair of I-beams, opposed anti-friction roller means between the first and second pair of I-beams, engageable along said upper and lower pairs of tracks respectively for centering said second pair of I-beams within said.

first pair of I-beams, and for facilitating longitudinal telescoping movement of said first and second pairs of I-beams, said roller means comprising transverse bearing sleeves welded to the web of said'second beam in alignment, an axle extending through said sleeves, and individual rollers on said axle outwardly of the web of said second pair of I-beams in engagement with theflange of the first pair of I-b'eams, and other of said individual rollers inwardly .of the webs of said second pair of I-beams in engagement with the flanges of the second pair of I-beams.

References Cited in the file of this patent UNITED STATES PATENTS Switzerland Aug. 16, 

